FIRED: By the Houston Astros, Manager BILL VIRDON, 51, after the Astros had slipped to fifth place in the National League West with a 49-62 record. In seven seasons under Virdon, the Astros had a 544-522 record and won the divisional championship in 1980. First Base Coach BOB LILLIS, 52, was named interim manager.
PURCHASED: By the Milwaukee Brewers, for a reported $200,000, the contract of Texas Rangers Pitcher DOC MEDICH, 33; by the Montreal Expos, Milwaukee Brewer Pitcher RANDY LERCH, 27, for an undisclosed sum.
SIGNED: By the Chicago Blitz of the USFL, 14-year NFL Quarterback GREG LANDRY, 35, to a two-year contract whose terms were not disclosed.
By the Minnesota North Stars, Right Wing BRIAN BELLOWS, 17, to a five-year contract reportedly worth up to $200,000 per year.
SYNDICATED: By Henryk de Kwiatkowski, at a record value of $36.4 million, CONQUISTADOR CIELO, the 3-year-old colt who has won seven consecutive races. De Kwiatkowski paid $150,000 for the horse as a yearling.
DIED: SALVADOR SANCHEZ, 23, WBC featherweight champion who was widely regarded as one of the world's finest boxers; in a three-vehicle collision; near Quer�taro, Mexico. Sanchez, who beat Danny Lopez in February 1980 for the featherweight crown, had a professional record of 43-1-1, with 31 knockouts (page 10).